I am not sure how messages work - do they require blocks to be confirmed before they can be verified?
I pasted everything back into my wallet and it verified
might be an error with electrum specifically, can you sign something simple along the lines of: This is a message from 15th September 2017 by chrisrovI pasted everything back into my wallet and it verified
edit: they've pmed me a different signed message, seems the account is indeed hacked.
